Calculator



Patented July Z6, 1892.

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CALCULATOR. No. 479,629. I"Patenfed July 26, 1892 ATTOHNEY *ms noms versus coA, mom-uma.. wAsnmoTcu, n. c.

(No Model.) 3 Sheets-Sheet 3.

C. H. GLARRIDGE. CALCULATOR.

' UNITED STATES PATENT OFFICE.

CHARLES H. CLARRIDGE, OF LIBERTYVILLE, IOVA.

CALCU LATO R.

SPECIFICATION forming part 0f Letters Patent N0. 479,629, dated July 26, 1892.

Application lled August 31,1891. Serial No. 404,250. (No model.)

To @ZZ w/tom t may concern:

Be it known that I, CHARLES H. CLAEEIDGE, of Libertyville, in the county of Jefferson and State of Iowa, have invented a new and lmproved Calculator, of which the following is a full, clear, and exact description.

My invention relates to improvements in calculators; and the object of my invention is to produce a simple and low-cost machine which may be quickly and accurately operated and which may be used to perform problems in addition, subtraction,multiplication, and division.

To this end my invention consists in certain features of construction and combinations of parts, which will be hereinafter described and claimed.

Reference is to be had to the accompanying drawings, forming a part of this speciiication, in which similar figures of reference indicate corresponding` parts in all the views.

Figure 1 is afrontperspective view of the machine with a portion broken away to show the connection between one of the sliding keys and its movable abutment. Fig. 2 is a broken enlarged detail View of the number-wheels and the mechanism for carryingthe tens. Fig. 3 is an enlarged detail sectional View showing the arrangement ot the keys, the movable abutment on which the keys rest, and the rackbar for operating the number-wheels, the section being taken on the line 3 3 in Fig. 1. Fig. 4 is an enlarged detail sectional view on the line 4 4 in Fig. 2, showing in side elevation the upper end of the rack-bar and the carrying mechanism. Fig. 4 is a broken detail View of the bent end of the carrier-bar and its actuatingcam. Fig. 5 is a vertical longitudinal section on the line 5 5 in Fig. 1 of the machine; and Fig. 6 is a broken detail sectional plan on the line 6 6 in Fig. 3 of the movable abutment and its lever which connects with the rack-bar.

In the accompanying drawings the machine has been shown as standing on one end, as it is more convenient to illustrate it in this way; but in operation the machine may be either fastened in an upright position, as shown in the drawings, or it may be laid upon its back. In the first case the machine is operated by pressing downward on the keys, and in the latter case by moving them forward.

ln constructing the machine the operative parts are preferably made of sheet metal, as in this way they may be cheaply constructed. The machine is provided with a main case 10, one side of which is closed by a plate 11, to which much of the mechanism is attached, and for convenience this plate will be called the base-plate, because a greater part of the mechanism ot the machine is carried by the plate. The case has also at one end, and may have on the back, a swinging lid 10, which enables the interior mechanism to be easily reached. In the upper portion of the base-plate are two rows of holes l2, through which the numbers on the number-wheels may be observed, and the numbers which appear in these holes show the result of the operation which has been performed on the machine. The lower rows of holes display the numbers which are the result of addition or multiplication, and the upper row displays the numbers which result from subtraction or division.

On the front side of the base-plate 11 are a series of vertically-movable keys 13, the upper ends of which are doubled outward and downward, so as to form finger-pieces14, and on these finger-pieces are inscribed the numerals from 1 to 9, which correspond with the numerals on the number-wheels. The fingerpieces are braced by braces 15, arranged between the iinger-pieces and the main keys. rlhese keys are arranged in banks, as best shown in Figs. 1 and 8,the keys appearingin successive rows and the keys of a horizontal row having the same number thereon. The keys are slotted near their lower ends, as shown at 1G in Figs. 1 and 3, and a pin 17 extends through these slots and limits the movement of the keys, the pin being held in place by screws which are secured to the baseplate and to the key-guard 18. This keyguard is of an approximately rectangular shape, and is secured to the front of the baseplate and serves asa keeper to cover the keys and guard them from injury. The lower end of the guard is strengthened by sleeve 19, which are arranged between it and the baseplate.

The keys 13, which are operated to work the machine, are arranged in vertical rows as well as in horizontal rows, the vertical rows thus IOO representing units, tens, hundreds, dac. These vertical rows of keys are separated by guidestrips 20, which are inclined, the upper ends being secured to the base-plate ll and the 5 lower ends to the guard 18, and to facilitate the easy and rapid working of the machine these guide-strips are differently colored, so as t divide the keyboard into periods which may be quickly distinguished by the operator. For instance, beginning on the units side of the machine the tirst two internal key-guides maybe red; the third, half red and half White; the fourth and fifth, white; the sixth, half I/ white and half blue; the seventh and eighth, blue, tbc.; but the colors are not arbitrary, and any distinguishing colors may be used.

Beneath each vertical row of ykeys isa vertically-sliding abutment 2l-that is, there is an abutment for the units row of keys, the tensrow of keys, the hundreds row, daer-and the keys marked 9 of each vertical row of keys are secured to the abutments, and consequently when a key is depressed the abutment will be moved, and the keys have successively longer limiting-slots according as the numbers upon them increase, so that when a key representing a small number is depressed the abutment 2l will be moved but little, and when a key representing a larger number is depressed the abutment will have a correspondingly greater movement. The keys are preferably made to overlap the sides of the abutment slightly, as shown in Fig. l, but this is not essential.

Theabutment 2l is folded up out of sheet metal so as to have a central recess, and itis of an approximately triangular shape, one iiat side being held to move on the base-plate ll. Near and in the upper end of the abutment is an opening 22, and the abutmenthas lips on opposite sides of the opening, which project through the slots 24 and are bent outward, thus forming-flanges 23, which overlap the base-plate ll and which serve as guides and enable the abutment to move easily up and down in the slot 24 in the base-plate.

An elbow-lever 24"L is centrally pivoted in the abutment 2l, so as to have one end project inward through the opening 22 in the abutment and through the slot 24 in the baseplate, and the upward movement of the end of the lever 245L contained in the abutment is limited by the top of the abutment and the downward movement by transverse pins 25. The inner end of the elbow-lever 24a connects with a vertical rack-bar 25a, which rack-bar is normally held upward by a spring 26, the tension of the spring being sufficientto overcome the weight of the keys 13, and this rackbar has at its upper end a rack 27, having upwardly-inclined teeth thereon. The rack 27 the rack-bar is secured to the rack, and it will be understood that the pin-holes may be made at dierent heights in the rack, so as to permit the correct adjustment of the rack-bar. The rack-bar is guided by the guide-plate 2S, which is secured to the base-plate and has guide-arms 2S, which extend inward between the several rack-bars, and the teeth on each rack-bar are adapted to engage the teeth of a ratchet-wheel 29, which ratchet-wheel is secured to the axis of the number-wheel 30, which number-wheel has the numerals from Zero to 9 printedon oneside and arranged at equal distances apart, and the numerals on the wheel register with one of theloweropenings 12 in the base-plate.

It will be understood that there is a rackbar, ratchet-wheel, and number-wheel for each vertical row of keys. The ratchet-wheel and the number-wheel connected therewith are v prevented from movin gbackward by the pawl 32, which is pressed into engagement with the wheel by a spring 33. The number-wheel 30 is provided with cogs upon its edge, and each number-wheel meshes with a similar wheel above it, and the upper number-wheels 3l have their numbers arranged to register with the upper row of holes in the base-plate.

The lower Vnumber-wheels are used for adding and multiplying, and as subtraction and division are the reverse of addition and multiplication itwill be seen that the upper number-wheels are adapted for subtraction vand division, as the wheels will move in the reverse direction to the lower wheels and the automatic arrangement for carrying ten in addition, which mechanism will be described below, will consequently serve to automatically borrow in the case of subtraction.

The rack-bars 27 are pressed into engagement with the teeth on the ratchet-Wheels 29 by the flat springs 34, which have flanges 35 at their lower ends, which facilitate their attachment to the base-plate 1l, and the upper or free ends of which press against the rackbars; but the springs 34 will yield sufficiently when the rack-bars are raised to permit the teeth of the rack-bars to jump the teeth of the ratchet-wheels.

On the back of each number-wheel 30 is a cam 36, which is separated from the ratchetwheel by a washer 37 and which terminates on one side in an abrupt radial shoulder, as best shown in Fig. 2, and this cam 36 is adapted to engage the lower bent end 37 of the carrier-bar 38, there being a carrier-bar for each set of number-Wheels, and the carrierbars are arranged vertically in the case and each bar is provided with a plate 39, to which it is secured, and the plate moves between the guide-plates 40, so that the bar may move accurately. The construction described in this paragraph is clearly shown in Figs. 2, 4, and 4, one of the number-wheels 30 being broken away in Fig. 2 to show the conformation of the cam 36 and its connection with a carrier-bar 38.

IIO

The plate 39 and the bar connected therewith are normally pressed downward by a spring 4l, and the cam 36 on the number'- wheel is adapted to gradually raise the bar against the spring and to finally release the bar by throwing it off. rlhis is done by the shoulder on the cam, and to this end the shoulder is arranged adjacent to the figure 9 on the number-wheel, so that the carrierbar will be operated at each revolution of the number-wheel. Each carrier-bar extends vcrtically through a sleeve 42, which sleeve has a llange 43 at its lower end, and the flange extends laterally from the sleeve and above the top of the rack-bar next in advance of the number-wheel, with which the carrier-bar is connected, so that when the carrier is moved downward in the act of carrying, as hereinafter described, it will move the rack-bar in advance, so as to turn the number-wheel of the next higher denomination far enough to register the amount carried.

The sleeve 42 has in one side a recess 44, which recess serves to engage the bent end 46 of an elbow-catch 45, which catch is pivoted on the upper portion of the carrier-bar and is normally pressed by a spring47, connecting its free end with the sleeve, so that when the bent end 4G of the catch is brought opposite the slot or opening 44 in the sleeve the bent end of the catch will immediately fly into the opening and hold the carrier-bar in a raised position, as shown at the left hand in Fig. 2.

The upward movement of the carrier-bar 38 is limited by a stop-plate 4S, which is secured to the base-plate 1l near the top by a screw passing through a slot 48' in the stop-plate, and opposite the plate and the carrier-bar is a releasing-plate 49, having at its lower end a pin 50, extending into the path of the upper free end of the spring-pressed catch 45, and when the carrier-bar is forced downward the catch is brought into engagement with the pin, which tilts the catch and withdraws the bent end 46 from the slot 44, thus permitting the continued downward movement of the carrierbar. The releasing-plate 49 is provided with a vertical slot 52 near its upper end, through which the fastening-screw 53 extends, and which thus permits the adj ustxnent of the releasing-plate, and the stop-plate 4S is provided with similar means of adjustment.

It will be noticed that the bent ends of the carrier-bars press somewhat on the cams of the number-wheels, and they thus serve as brakes to preventthe numbers on the wheels from being carried too far by the highest set of number-wheels; but the set representing the highest numbers are not provided with carrier-bars, and to take the place of them a flat spring 54 is secured to the base-plate and is arranged to press upon one of the numberwheels so as to prevent the wheel from traveling too far, and thus rendering the machine inaccurate.

In solving problems involving moderatelysized numbers the numbers may be carried in the head; but where larger numbers are involved it is difficult for some people to retain them, and to facilitate the easy and accurate working of the machine a slate 55 is secured to the base-plate near the top of the machine, and the numbers which it is necessary to remember may be written upon the slate.

In simple subtraction the machine only complicates the operation, but in successive subtractions and in division the machine is useful, as it vsaves paper, may be easily worked, and is absolutely accurate.

To illu strate the operation of the machine, it is necessary to go into a simple operation, which is as follows: The first number of the series to be added will appear in the lower row of holes 12, and in adding the units-column iE 0 is to be added units-key marked 9 is depressed, or if any other unitis to be added its particular key is depressed, and the keys are timed in relation to the rack-bars and number-wheels, so that when a keyis depressed the number-wheel with which it is connected will be moved so as to bring a series of numbers past one of the holes 12 corresponding to the number of the key. Suppose the units-key marked 9 is depressed. It follo'ws that the combined numbers will represent a greater number than 10, and consequently there will be one to carry; but the operator need pay no attention to this, as the machine carries automatically as follows: When the number 9 has been reached, the n u mber-wheel will have made nearly a revolution, and if the wheel goes farther the cam 3G throws oft the end S7 of the carrier-bar 38 and the sprin g 41 forces the carrier-bar downward and takes with it the sleeve 42 and the next rack-bar 25, which will be the rack-bar in the tens-column. lVhen a rack-bar has been sufficiently depressed to move the tens numberwheel 30 a distance ot one ligure, the upper end of the' elbow-catch 45 will have been brought into engagement with the releasingpin 50, which will thus throw the catch out of the slot 44 in the sleeve 42, and the sleeve will move upward and the cam 36 as it revolves will return the carrier-bar to its original position. The number-wheel 30, directly operated by a key, is moved by the depression of the movable abutment 21 and the rackbar connected with the number-wheel; but from the foregoing description it will be seen that the carrier-bar is moved and a number carried without the immediate movement of a finger-key. 1t will be seen that this addition of numbers may be carried out to any extent, and as multiplication is a series of additions the multiplication will be performed in the same way.

To use the machine for subtract-ing or dividing, reference is to be had to the upper row of holes 12, and as the upper number-wheels move in the reverse direction to the lower number-wheels it will be seen that these operations maybe performed in the same way as the adding operations above described 5 but as the IOO IIO

wheels move in reverse directions instead of carrying one one will be borrowed by the carrier mechanism.

I am aware that it is not new to provide a machine with numbered keys adapted to operate numbered wheels geared together so as to turn in opposite directions and to automatically carry the tens, and I do not claim these features, broadly, as my invention; butthe construction which I have shown and described enables the machine to be cheaply built and rapidly operated, and, furthermore, a machine built in this manner will be very durable.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl. A calculatorcomprising abase-plate having rows of holes therein, number-wheels pivoted on the base-plate and having numerals to register with the holes, rack-bars geared to the number-wheels, rows of numbered fingerkeys adapted to move upon the base-plate, a sliding abutment arranged at the end of each of the finger-keys, and elbow-levers pivoted in the abutments and having their inner ends connected with the rack-bars, substantially as described.

2. A calculator comprising a plate having holes therein, number-Wheels pivoted on the plate and having numbers to register with the holes, rack-bars geared to the number-wheels, sliding abutments arranged beneath the rows of keys and connected by lever mechanism with the rack-bars, and a series of numbered finger-keys arranged in rows to press upon the sliding abutments, the keys having longitudinal slots of dissimilar lengths and limiting-pins extending through the slots, substantially as described.

3. In a calculator, the combination, with the revoluble number-wheels having a gear mechanism to revolve them,of cams secured to the wheels and provided with shoulders on one side, movable rack-bars adapted to operate the wheels, spring-pressed carrier-bars adapted to engage a cam of one wheel and a rackbar of a wheel in advance of it, and a releasing device to limit the movement of the carrier-bars, substantially as described.

4. In a calculator, the combination, with the rows of number-wheels and the movable rackbars adapted to operate the wheels, of cams secured to the wheels and provided on one side with a shoulder, movable spring-pressed carrier-bars having their ends in engagement with the cams, sleeves mounted on the carrier-bars and adapted to overlap the rackbars, a spring-pressed catch to fasten the carrier-bars and sleeves together, and an automatic releasing device for the catch, substantially as described.

5. A calculator comprising a base-plate, rows of keys held to slide on the base-plate, said keys having outwardly-bent and numbered ends, sliding abutments mounted on the baseplate below each vertical row of keys, elbowlevers pivoted in the abutments, movable rack-bars carried by the elbow-levers, numbered wheels geared together and held to turn opposite holes in the base-plate, said wheels having a ratchet connection with the rackbars, cams on the number-wheels, springpressed carrier-bars held to slide on the baseplate, each carrier-bar being adapted to engage a cam on a number-wheel and the rackbar in advance of it, and a device for releasing the carrier-bars and limiting their movement, substantially as described.

6. The combination, with the number-wheels having cams on their back and the rack-bars geared to the number-wheels, of spring-pressed carrier-bars held to slide near the rack-bars, the carrier-bars having bent ends to engage the cams, sleeves mounted on the carrier-bars and adapted to engage the rack-bars, and a releasing device to free the rack-bars and carrier-bars, substantially as described.

CHARLES Ill. CLARRIDGE.

Witnesses:

` JAMES CowAN, ISRAEL TROUT. 

